Shear pin coupling



g- 1952 H. w. THYLEFORS SHEAR PIN COUPLING Filed July 10, 1946 m/\ 9 zlm// M INVENTOR.

ATTORNEY/5 6 w, fl. 6 l T 1 h Z Wu C L T w H Patented Aug. 5, 1952 UjNlTED' STATES PATENT OFFICE assignor to v I Sweden, a corporation of Sweden v I Application July 10, 1946, Serial No. 682,630

Aktiebolaget Separator, Stockholm,

, :In Great Britain August 28, 1945 .GClaims. .(01. 6448) With centrifugal separators the liquid to be separated is often fed to the bowl by means of a pump in the feed pipe, and also the separated liquid is discharged from pump in the discharge pipe or pipes. The pumps are preferably carried out as a separate aggregate which can be attached to the separator, and for this purpose they are generally placed on a bracket or a shelf which is screwed to the frame. The pumps are preferably driven from the worm wheel shaft of the separator. Gear pumps are generally used. The liquid to be separated often contains solid particles, so that it is necessary, especially with the kind of pumps mentioned, to use some arrangement which protects the gear wheels'from being damaged by the influence of the solid particles. In the present invention a so-oalled break-coupling is for this purpose arranged between the worm wheel shaft and the pump or pumps.

In the accompanying drawing, the single illustration is a vertical sectional View of a construction embodying the invention. Referring to the drawing, the structure there shown comprises a separator frame I and a bracket 2 fixed to the frame by means of screws 3. The bracket carries one or more pumps 4. Generally there is used one pump in the feed pipe and one in the discharge pipe of the separator. The driving movement is transmitted to the pump shaft 5 by means of two gear wheels 6 and I. The last mentioned wheel is connected with the worm wheel shaft 8 of the separator by a special coupling, consisting of an intermediate part 9 screwed to the worm wheel shaft, which part is connected with the gear wheel 1 by means of a coupling member Ill. The said member In consists preferably of a cylindrical pin placed in aligned bores in the part 9 and. the wheel 1, as shown in the figure. The pin or coupling 10 is kept in position bymeans of a screw I l in the part 9. The part 9, the member 10 and the gear wheel 1 form, as is to be seen from the drawing, when mounted together, a unity rigidly connected to the worm Wheel shaft. A part of the bracket has the shape of an open hood turned towards the frame, which hood encloses the gear wheels. The coupling itself protrudes through a hole [2 in the hood and is in the main placed outside the hood and protected by a separate hood l3, which is screwed to the bracket. After removing the hood 13 the unity consisting of the part 9, the member In and the gear wheel 1 becomes accessible from the outside and can be detached without any other machine parts having to be displaced.

the bowl by means of a between the worm wheel shaft As is said above, the driving movement istransmitted from the worm wheel shaft 8 to the ear wheel I by means of the coupling member l0. At too high a load, due for instance to solid particles in the liquid to be separated, the coupling member is broken, thusbreaking the rigid connection 8 and the wheel I. Damaging of the pump or pumps is hereby avoided. With a view to this such a dimension is given to the member In that only a certain maximum driving moment can be transmitted.

If the coupling member has broken one need only remove the hood l3, screw off the part 9 from the worm wheel shaft and remove the part 9 and the gear wheel I. Then these details can in a suitable place be mounted-together by means of a new coupling member, and as a whole again be placed in the machine. After the, mountin of the hood 13 the separator is again ready to be used. It is of importance that the replacing of the broken member by a new one can be carried out in a suitable place and that the wheel I and the-part 9 can as a whole again be put in their place in the separator, the mounting work on the separator itself thereby becoming the least possible. This is of advantage with regard thereto that the separators are often erected in very restricted spaces and therefore more or less difiioult to get at.

By placing the break-coupling between the worm wheel shaft 8 and the gear wheel I the advantage is obtained that if several pumps are simultaneously driven the functioning of all of them ceases at the breaking of the coupling member. The arrangement according to the drawing has also the advantage that the pieces of a broken member in cannot fall down into the interior of the separator frame, the play between the hole l2 and the wheel 1 being so small that this is prevented. The said pieces are instead kept within the hood l3, and there is no danger that same could damage the parts enclosed in the frame.

Other embodiments are possible. Thus the part 9 could be dispensed with if for instance the end of the worm wheel shaft is provided with an open slot in which the coupling member ID directly engages at the mounting of the parts on the worm wheel shaft.

I claim:

1. In a machine having a shaft provided with a free end, a rotatable device, and a driving connection between the shaft and device including a driving element rotatably mounted on the shaft and slidable off the free end thereof, the imbreakable coupling member extending transversely of the shaft through said aligned trans verse openings in the driving element and releasable part, the coupling member being, rotat able with said part and element relative to the" shaft, and a threaded driving connection be= tween the releasable part and thejclrive shaft to"? accessible from outside the frame, and a removable hood mounted-on the outside of the frame to receive the outwardly projecting pa'rt'ofthe coupling, including said coupling member.

4. The improvement as defined inclaim 1 comprising also a releasable device mounted on said torque-transmitting part andclamping said coupling member in itsdriving -position in said openings.

5. In a machine having a shaft and a device to be driven from the shaft, a driving'connection be permit release of said part by rotation thereof]. relative to the shaft, whereby said coupling memher, releasable part and driving element are held" tween the shaft and device, which comprises a driving element having a loose fit on the shaft, a torque-transmitting member removably threaded on the shaft and disposed at least partly within the driving element, said member having a part opposing one end ofv the shaft and provided with an opening extending transversely of but beyond said end of the shaft, the driving element having an opening aligned with said first opening, and a shear pin disposed in the opening in said memher; and projecting into said aligned opening in the driving element, whereby said element, meme her and pin are removable asa unit from said end fi h ha t.

6. A drivingconnection according to claim 5,

v comprising'also; a; set screw extending axially of the shaft in said opposing part of the torquetransmitting member, the set screw engaging the pin to hold it in position. 1

HENRIC WILHELM THYLEFORS.

fileof'this patent:

UNITED STATES PATENTS Number 7 Name. Date 718,461; Hult et a1." Jan. 13, 1903 1,006,758," Mei/miles" V oct.,24,' 1911 1,383,854 Rath'bun' July 5, 1921' 1,493,188,; Campbell May 6,ff1'9 2 f4 1,510,557,: Coleman p Oct, 7, 1924" 1,758,180, Stein'j May 13, 1930 1,805,879 McKenny' May19, 1931,". 1,849,174; l Mar. 5,1932, 2,094,632? Shaffer g g Oct'.'-5,f19 37' 21 1 1269; Peltz Jan. 17; 1939': 2,298,315 Simmons Oct. 13,1942.

FOREIGN PATENTS. Minter Country Date 112,372 1 England 1 ;1;Jan;10,1913" 195,524" England I 1923'; 

